What's thr solution to the quadratic equation x^2+2x-4=O

quadratic equation:
to solve ax² + bx + c = 0
x = [–b ±√(b²–4ac)] / 2a
x = [–2 ±√(4+16)] / 2
x = [–2 ±√(20)] / 2
x = [–2 ±√(4•5)] / 2
x = [–2 ± 2√(5)] / 2
x = –1 ± √5
or
x = –1–√5 , –1+√5

By completing the square:
(x + 1)^2 -5
x = 1 + or - 5

x = (-b + or - sqrt(b^2 - 4ac)) / 2a

a = 1
b = 2
c = -4

x = (-2 + or - sqrt((-2)^2 - 4(1)(-4))) / 2(2) = -2/4 + or - sqrt(20) / 4

Cannot solve by factorisation. Use quadratic formula.

x^2+2x+1=4+1=5
(x+1)^2=5
x+1=+-sqrt(5)
x=-1+-sqrt(5)

Use the formula !